Development of Low Pressure Ratio Vectoring Nozzles for V/STOL Aircraft

Results of a parametric test program of low pressure ratio deflected nozzles show the performance changes to be significant for vectoring nozzles and variations in nozzle thrust coefficients should be included in engine cycle trade studies to obtain realistic aircraft performance. Low pressure ratio deflected nozzle performance is shown to be sensitive to nozzle pressure ratio, nozzle contraction ratio, turning radius, diffuser area ratio and the presence of an integral core flow exhaust stream. The effectiveness of venting the inside surface of the nozzle turn is also demonstrated.